Rock-cutting tool



April 8, 1930.

o. ROLFSEN ROCK CUTTING TOOL April 8, 1930. o. ROL FSEN 9 ROCK CUTTING TOOL Filed July 26, 1929 2 Sheets-Sheet 2 ll ll MJIEJIQ Patented Apr. 8,' 193!) ATE.

OLE ROLFSEN, OF KNIVSO, NEAR HALDEN, NORWAY ROCK-CUTTING TOOL Application filed my as, 1929. Serial no. 381,28'.

The present invention relates to tools for working in earth, rock, metal, wood and the like and more particularly to tools which comprise discs mounted on a rotating shaft 5 and having hammer heads in connection therewith.

The hammer heads in rockcutting tools of this kind generally have a polygonal form and are pivoted with loose play on pins par- 10 allel with the axis of the rotating shaft.

These pins owing to the jerky rotation of the hammer heads and the impacts of the hammer heads with the rock etc. are subjected to severe strains, and the object of the present 1 invention is to provide a rock cutting tool of the kind specified in which these strains on the supporting pins or trunnions for the hammer heads are reduced.

This is obtained in accordance with the 99 present invention by providing between the pin serving as a trunnion for the hammer head and the rotating discs carrying the said pins elastic members which permit a limited movement of the said pinsrelative to the discs in all directions in a plane perpendicular to the axis of the pins.

In accordance with a preferred embodiment of the invention the connection between the pins and the rotating'discs carrying the same comprises annular elastic members, such as rubber discs or the like, said discs fitting tightly about the pins and being themselves fitted into suitable openings in the discs.

Although it is preferred to use rubber discs for this purpose, it is also possible to substitute for these discs other elastic members such as steel springs or the like.

In accordance with another embodiment of my invention I provide a hollow trunnion for the hammer head, said hollow trunnion being supported on a core pin by means of a suitable elastic member, such as a rubber sleeve or suitably shaped steel springs.

Some embodiments of the invention are illustrated on the drawings.

Figs. 1 and 2 illustrate diagrammatically in cross sections and axial view a rotating tool of the kind referred to. On these figures the hammer pins are indicated by 1, the rotatmanner.

ing discs by 3, 4 and the hammer head's by 13.

Fig. 3 is an axial cross sectional View of a hammer pin in accordance with my invention. Fig. 4: is a section on the line IV'-IV of Fig. 3.

Fig. 5 shows an axial section throu h a hammer trunnion in accordance with a modified form of the invention, and Fig. 6 is a cross section on the line VI-VI of Fig. 5.

Fig. 7 is a sectional view, similar to Fig. 3 of a further embodiment of the invention, and Fig. 8 is a cross section on the line VIIIVIII of Fig. 7. Fig. 9 is 'a sectional View similar to Fig. 3 of a further embodiment of the invention, a nd Fig. 10' is a cross'section on the line X'X of Fig. 9'.

In accordance with the embodiment illustrated on Fig. 3, the trunnion comprises a core pin 1 and a sleeve 2 of suitable wear resisting material fitted on to the same; The inside surface of the hammer head, as will be understood, bears againstsl'eeve 2, the hammer head being not shown on the drawing.

Pin 1 is mounted 'in the parallel rotating discs 3, 4 by means of annular elastic members 5, 6 of rubber or similar material, said discs 5, 6 being secured to the rotating discs 3, 4 by means of suitable cover plates 7, 8 riveted on to the'd'isc's 3, 4 or mother suitable The elastic rubber discs 5, 6 fit tightly about pin 1 and project a certain distance inside the inner circumference OiE the openings 9, 10 in 'discs 3, 4 adapted to receive the same, so that the pin 1 is given a certain freedom of movement in all directions in a is interposed between the trunnion sleeve 2 and the pin 1 an annular cushion 12 of rubber or the like, so as to permit the trunnion sleeve 2 freedom of movement against the elasticity of the cushion with regard to the pin 1, which in this case is mounted stationary in discs 3, 4.

It is preferred in connection with this embodiment of the invention to make the trunnion sleeve slotted so as to allow for expansions and contractions of the rubber cushion 12.

The embodiment of the invention illustrated on Figs. 9 and 10 is similar to the one illustrated on Figs. 7 and 8, the only diiference being that slotted star-shaped steel springs 11 of the kind illustrated on Figs. 5 and 6 are substituted for the rubber cushion between trunnion sleeve 2 and pin 1.

It will be observed that in all the embodiments of the invention above referred to, the trunnion, against the exterior surface of which the interior surface of the hole in the hammer head is bearing, is given freedom of movement against the elastic action of springs or the like with regard to the rotating discs 3, d carrying the hammer head pins.

The invention is not limited to the use of any particular elastic means for giving the said freedom of movement to the hammer head trunnion, and although rubber cushions or steel springs are preferred, other means or elastic members formed by a combination of rubber and steel may be employed for the same purpose.

Claims:

1. In a rotating rock cutting tool a rotating frame, a number of hammer heads, trunnions for rotatably connecting said hammer heads with said rotating frame and elastic means for connecting said trunnions with said rotating frame.

2. In a rotating rock cutting tool the combination with rotating hammer heads, trunnions for the said rotating hammer heads, a rotating frame member for supporting said trunnions and elastic means for connecting said trunnions with said rotating frame member.

In a rotating rock cutting tool, a rotating frame, a number of hammer heads, trunnions for rotatably connecting said hammer heads with said rotating frame and elastic means comprising an annular body of rubber for connecting said trunnions with said rotating frame.

In testimony wheref I aflix my signature.

OLE ROLFSEN. 

